Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-09-2013, 05:56 AM   #1
Senior Member




Join Date: May 2012
Posts: 118
Used Extension Tube then Lens Stopped Reading Aperture??

Hello! Question for you, I'm not sure what happened to my lens. I just got a cheap metal set of extension tubes so I can use all of my lenses for closeups. I put the extension tubes on with my Tamron 28-75 and it worked great. Little tough to get the piece apart from the lens - realized I had to pull out the little pin on the side to release it, so not that big of a deal. I noticed when I put the extension tubes on with the lens, it read everything except the aperture. I thought ok, it's just a side effect from the tube or something, being it's not the auto focus type of tube I knew I was going to have to do manual mode, which I have no problems with. Then I took the lens out yesterday to take some regular shots, snapped it directly on to the camera and realized it still wasn't reading the aperture. It reads everything else, but the aperture just says "F--" and the lens will no longer work in auto mode. I shot with it in manual mode yesterday and it worked fine, but what the heck happened? It isn't a setting on my camera because I snapped on another lens and it worked fine. The Tamron lens does have an aperture ring, did it somehow get stuck/locked? I am confused, help!!

This is the lens: Tamron 28-75mm F2.8 AF XR Di LD Macro SP Lens Reviews - Tamron Lenses - Pentax Lens Review Database

OH and while I'm in the help forum, another thing I've noticed is sometimes when I look through the viewfinder, everything looks blurry (like yesterday). Regardless of the lens, things looked blurry and I had to use autofocus for a long time, which I hate, but the photos turned out sharp, not blurry. It improved as I was using it and then I was able to switch to manual focus, but I've had this issue before and can't figure it out either!

I have the Pentax K-5.

Thanks!

09-09-2013, 06:08 AM   #2
Inactive Account




Join Date: Dec 2008
Location: North Carolina
Photos: Albums
Posts: 1,720
You probably took the Tamron's aperture ring out of A when you used it on the extension tube, the lens must be in A mode for automatic exposure modes to work. If it is in A mode the electrical contacts on the lens are likely just dirty, clean them with a lint free cloth with some alcohol on it.

The second question sounds like you might be bumping the viewfinder diopter. It is a little slider on the top of the viewfinder, move it back and forth until the numbers displayed in the viewfinder are sharp. It is there to adjust the viewfinder to your eyesight.
09-09-2013, 06:14 AM   #3
Senior Member




Join Date: May 2012
Posts: 118
Original Poster
QuoteOriginally posted by elliott Quote
You probably took the Tamron's aperture ring out of A when you used it on the extension tube, the lens must be in A mode for automatic exposure modes to work. If it is in A mode the electrical contacts on the lens are likely just dirty, clean them with a lint free cloth with some alcohol on it.

The second question sounds like you might be bumping the viewfinder diopter. It is a little slider on the top of the viewfinder, move it back and forth until the numbers displayed in the viewfinder are sharp. It is there to adjust the viewfinder to your eyesight.

Thank you for the quick response, I am not at home right now so I will take a look at the lens this afternoon, but what you are saying is there should be something on the lens itself that switches in and out of auto mode??
09-09-2013, 06:23 AM   #4
Inactive Account




Join Date: Dec 2008
Location: North Carolina
Photos: Albums
Posts: 1,720
The aperture ring, it should be on A, there is a small button that must be pressed to move it into or out of A. Under normal circumstances it should always be on A, the only exception being using extension tubes that don't have the ability to pass through the information from the lens to the camera.

09-09-2013, 06:32 AM   #5
Senior Member




Join Date: May 2012
Posts: 118
Original Poster
QuoteOriginally posted by elliott Quote
The aperture ring, it should be on A, there is a small button that must be pressed to move it into or out of A. Under normal circumstances it should always be on A, the only exception being using extension tubes that don't have the ability to pass through the information from the lens to the camera.
I will look for that! I didn't see anything right off when I looked yesterday but I was in a hurry so I might have missed it!
09-09-2013, 07:19 AM   #6
Veteran Member




Join Date: May 2009
Location: Twin Cities, MN
Posts: 2,869
QuoteOriginally posted by laughlady99 Quote
I just got a cheap metal set of extension tubes so I can use all of my lenses for closeups....
There is basically only 1 set of extension tubes that actually communicate aperture between the camera and the lens. They are the Kenko Auto Extension tubes and typically run $100-150 and are pretty rare. Your description of the tubes you bought leads me to believe these are not the tubes you bought, but rather a $15 set of metal tubes on ebay or some other site, am I correct? If yes, you'll have to use the camera in M mode and use the green button for stop down metering (search the forum for info on that). You're not going to get auto aperture with any tubes but the ones I noted (there might be some even rarer auto aperture tubes, but the Kenko tubes are the only ones that are usually around/available occasionally).
09-09-2013, 10:48 AM   #7
Pentaxian
bluestringer's Avatar

Join Date: Nov 2011
Location: Cotton fields of South Georgia
Photos: Gallery | Albums
Posts: 2,438
If the tubes do not have contacts, then it will not work in auto mode. You can take a cheap set of 2x converters, take the glass out, and you have a cheap set of auto tubes.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
aperture, extension, extension tube, lens, mode, pentax, pentax help, tamron, tube, tubes, yesterday
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Extension Tube Stuck on Lens pippin65 Pentax K-30 & K-50 4 03-28-2014 09:47 PM
How to get lens off extension tube? telly0050 Pentax K-5 8 09-17-2012 09:10 AM
Using a lens without aperture with with basic extension tube gangleflops Troubleshooting and Beginner Help 5 08-13-2012 02:26 AM
Macro K-5 kit lens with extension tube Darrell Raw Photo Critique 5 05-10-2012 06:32 PM
Pentax 18-55 lens won't mount - It used to..just stopped tfbrenizer Pentax SLR Lens Discussion 17 05-06-2012 04:57 PM



All times are GMT -7. The time now is 04:15 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top